Prevalence of Salmonella species and their antimicrobial susceptibility pattern at a tertiary care hospital, Gujarat

Abstract

Background: Salmonella species are major pathogens causing enteric fever and bloodstream infections in endemic regions like India. Despite improvements in sanitation, the disease burden remains high. Increasing antimicrobial resistance (AMR), particularly fluoroquinolone (ciprofloxacin) resistance, has restricted therapeutic options.

Material and methods: This retrospective cross-sectional study was conducted in the Department of Microbiology, GMERS Medical College & General Hospital, Vadodara, Gujarat, using blood culture records for the period September 2024 to September 2025. A total of 1234 blood culture samples from clinically suspected enteric fever cases were processed using the BACTEC FX 40 automated blood culture system.  Isolates were identified by biochemical tests and serotyping. Antimicrobial susceptibility was determined by Kirby–Bauer disc diffusion method on muller –hinton agar as per CLSI guidelines 2024. 

Results: Out of 1234 blood culture samples processed during the study period, 73 (5.9%) yielded Salmonella isolates. The majority were Salmonella Typhi (91.8%, n=67), followed by Salmonella Paratyphi A (6.8%, n=5) and Salmonella Paratyphi B (1.4%, n=1). Most cases occurred in the pediatric age group (≤12 years), accounting for 65 cases (89.0%). Antimicrobial susceptibility testing showed that all isolates showed susceptibility to ceftriaxone, azithromycin and imipenem. Chloramphenicol retained high susceptibility (97.0%), followed by ampicillin (83.6%) and co-trimoxazole (80.6%). High resistance was observed to ciprofloxacin (90.4%).

Conclusion:  Salmonella bloodstream infections remain a major health burden in pediatric patients. High fluoroquinolone resistance highlights the need for continuous surveillance and rational antibiotic use.